#![cfg(test)]

use core::panic::PanicInfo;

#[panic_handler]
fn panic(info: &PanicInfo) -> ! {
    serial_println!("[failed]\n");
    serial_println!("Error: {}", info);
    exit_qemu(QemuExitCode::Failed);
    loop {}
}

/// This function is hooked up to the #![test_runner] attribute made possible by the
/// https://doc.rust-lang.org/unstable-book/language-features/custom-test-frameworks.html unstable
/// feature. cf. https://os.phil-opp.com/testing/
pub fn test_runner(tests: &[&dyn TestFunction]) {
    serial_println!("Running {} test(s)", tests.len());
    for test in tests {
        test.run();
    }

    exit_qemu(QemuExitCode::Success);
}

pub trait TestFunction {
    fn run(&self) -> ();
}

impl<T> TestFunction for T
where
    T: Fn(),
{
    fn run(&self) {
        serial_print!("{}...\t", core::any::type_name::<T>());
        self();
        serial_println!("[ok]");
    }
}

/// Exits qemu by writing to a special qemu emulated port.
pub fn exit_qemu(exit_code: QemuExitCode) {
    use x86_64::instructions::port::Port;
    unsafe {
        let mut port = Port::new(0xf4); // isa-debug-exit port, see Cargo.toml
        port.write(exit_code as u32);
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq)]
#[repr(u32)]
pub enum QemuExitCode {
    Success = 0x10,
    Failed = 0x11,
}